Nitrogen mineralization in high elevation forests of the Appalachians. I. Regional patterns in southern spruce-fir forests |
| |
Authors: | Russell H Strader Dan Binkley and Carol G Wells |
| |
Institution: | (1) School of Forestry, and Environmental Studies, Duke University, Durham, NC 27706, USA;(2) School of Forestry, and Environmental Studies, Duke University, Durham, NC 27706, USA;(3) USDA Forest Service, Southeastern Forest Experiment Station, Forest Sciences Laboratory, Research Triangle Park, NC 27709, USA;(4) Present address: Dept. of Forest Management, Oregon State University, Corvallis, OR, 97331;(5) Present address: Dept. of Forest and Wood Sciences, Colorado State University, Ft. Collins, CO, 80523 |
| |
Abstract: | Annual and seasonal rates of net nitrogen mineralization were determined for 19 sites in the spruce-fir forests of the Southern
Appalachian Mountains. These sites included high and low elevation stands of red spruce (Picea rubens Sarg.) and Fraser fir (Abies fraseri (Pursh.) Poir.) on east and west exposures on Whitetop Mountain, Virginia; Mt. Mitchell, North Carolina; and Clingman's Dome
in the Great Smoky Mountains National Park. Mineralization rates were determined using in situ soil incubations in PVC tubes
with ion exchange resin bags placed in the bottom of the tubes to collect leachate. Throughfall was collected in resin bags
placed in the top of the tubes. Average initial NH4-N + NO3-N ranged from 0.6 to 4.8 kg N/ha across all plots, and average mineralization rates ranged from 26 to 180 kg-N ha−1 yr−1. Throughfall ranged from 18 to 32 kg-N ha−1 yr−1 with NH4-N accounting for about two-thirds of the throughfall N across all sites. Throughfall and mineralization rates were not related
to elevation or exposure. The high rates of N mineralization and relatively high nitrate concentrations indicate that leaching
losses of nitrogen and associated cations could be substantial.
Requests for offprints |
| |
Keywords: | Picea rubens Abies fraseri acid deposition forest decline |
本文献已被 SpringerLink 等数据库收录! |
|